Abstract:

To clarify the species composition and inter-specific association of Xanthoceras sorbifolia communities in Shanxi Province,we carried out a series of typical sampling investigations.Based on the 2×2 contingency table,we used variance ratio(VR),χ ² test,Pearson’s correlation and Spearmen’s rank correlation to analyze the inter-specific association among the 231 species-pairs of the 22 dominant species in X.sorbifolia communities.Variance analysis showed that the whole of inter-specific associations of the 22 dominant species were significant negatively correlated,and the distribution of the species was relatively independent.The χ² test,Pearson’s correlation and Spearmen’s rank correlation analysis among the 231 species-pairs of the 22 dominant species showed that 78,64 and 79 species-pairs were positively correlated,153,167 and 152 species-pairs were negatively correlated,and the positive and negative ratios were 0.51,0.38 and 0.52,respectively.The conclusion showed that there were no significant or only low correlations among the most of 231 species-pairs.According to the ecological characteristics of species,and by using the TWINSPAN and DCA methods,the 22 dominant species were divided into four ecological species groups.The results showed that the plants of X.sorbifolia communities are not very stable and in a stage of succession change.

Key words: Xanthoceras sorbifolia community, dominant species, inter-specific association, inter-specific correlation, ecological species group, Shanxi Province